CH. XII] C. TAXONOMIC 133 



species, when it begins to move into a greater range of conditions 

 and climates, that it begins to show a range of smaller forms, 

 which to the writer represent later stages in the continually 

 diminishing mutation that began with the formation of the 

 family, the genus, and this particular species. It is to be noted 

 also that the great range of form only shows as a rule in species of 

 the larger (or older) genera. When it does occur in species of 

 small genera, the genus usually has a wide range, showing that 

 it is probabl}^ old in its own circle of affinity. 



It is verv difficult to see whv on the Darwinian scheme the 

 only genera of a very small family ("relics ") should be separated 

 by as large distinctions as those that separate the sub-genera of a 

 large family (p. 112), and why those distinctions should be so 

 often such as are incapable of having intermediates, like many of 

 those given in Appendix I. And it is equally difficult to see why 

 the species of a single genus making up a family by itself should 

 be grouped by such wide divisions as are instanced upon p. 79, 

 again distinctions that do not often admit of intermediates. 



From the differentiation standpoint, the puzzle presented by 

 these little "Jordanian" species, such as were described in 

 Draba, for example (22), and which no stretch of imagination can 

 show to be the commencement of new species derived by gradual 

 adaptation upon the Darwinian plan, becomes quite simple. They 

 are simply the last wavelets of the great disturbance that was 

 made when the parent of the Cruciferae was formed from some- 

 thing else by a "large" mutation that gave it tetradynamous 

 stamens and the rest of the outfit of the Cruciferae. 



The second axiom is 



2. Sjjecies of the larger genera in each country vary more frequently 

 than the species of smaller genera. 



Here again the variation w^as put down to the "success" of the 

 larger genera, which were going on to develop new species, but, 

 as explained above, it is much simpler to put it down simply to 

 the age of the genera and size or area of the species, the larger 

 being older, and having had more time to develop smaller muta- 

 tions than that which gave the ordinary species. 



3. Many of the sjjecies included within the larger genera resemble 

 varieties in being very closely but unequally related to each other, 

 and in having restricted ranges. 



This is exactly what shows in the hollow curves. In the large 

 genera there is a great proportion of species of small area, far 



